exhibited on every section. it is conjectured that this curious process was the first attempt of the ancients to preserve colours by fusing them into the internal part of the Glass. (See PLATE 3, figs. 6, 7, 8.)

In the British Museum are many of these interesting curiosities of Glass Mosaic work, some of perfectly white clear Glass in the form of leaves or flowers, interwoven in the midst of a dark green ground; the refraction of the latter upon the white edges of the flower pattern, producing an intermediate, blended effect. Most of the pieces are small, and some of the patterns are very minute; but great study of effect, and much taste as well as skill, are apparent in their execution. There are also numbers of fragments of white enamel upon blue, and white upon amethyst grounds, of well executed designs in relief; probably, executed by eminent Roman or Grecian artists resident in Rome. (See PLATE 3, fig. 10.) On precious stones becoming rare or expensive, artists had recourse to artificial gems; some of them are prepared with two or three layers of colours in opaque Glass welded to each other, of oval or round forms, to imitate real stones; and these crude pieces, when worked and ornamented by the lathe, enabled the gem engravers to meet the public demand at a comparatively small cost. Artists having thus become accustomed to work Glass in the manner of cameos, the execution of larger objects of taste—viz., vases like the Naples, and Portland—was comparatively easy.* (See PLATE 1.) A great